Production of hydrogen



Nov. 1 1930. F. T. SNYDER 3 PRODUCTION OF-HYDROGEN Filed Dec.- 16, 1925fi'e/en'ck Snyder Patented Nov. 3, 19st PATENT OFFICE FREDERICK T. SNYDER, OF NEW CAN-LAN, CONNECTICUT ahzonucrron or HYDROGEN Applicationfled December 16, 1925, Serial- No. 75,795,-and in Canada March 12,1925.- v

This invention relates broadly to the art of hydrogenating hydrocarbonsand carbo-. hydrates, and more particularly to a method or process ofproducing, at low cost and in 5 large. quantities, hydrogen or gasmixtures containing a large amount of free hydrogen and suitableforhydrogenation processes.

Generally s'peaking,;the inventionresidesin cracking natural gas 'or'gasdistilled-from ing the same in contact with hot refractory material inclosed chambers with exclusion of air, and burning with air in thechambers the carbon de osited from the cracking operation, to relieat'the refractory material. These [operations are-performed alternately. Itis, of course,'well known that methane, thev chief constituent ofnatural gas, can be dissociated into hydrogen and carbon by heating thegas to a sufiiciently high temperature with exclusion of air. Othergases or hydrocarbon vapors with high hydrogen content ma be cracked inthe same way,

according to the nature of the original gas or vapor. The carbondeposited when natural as is cracked is suflicient in amount, 1 whenurned with air, to furnish more heat than necess'ar to eflectthecracking. The excess heat 0 sets-loss by radiation and may be used toheat'the produced highhydrogen to generate steam, or for other purposes.ii; the economic accomplishment of these results, it is essential thatthe gas should pass through the cracking chamber tions the incoming coldgas and. cold air operate to sweep the heat toward the centre centre.Preferably v the interior of the cracking chamber is a brickworkchecker.

To facilitate comprehension of the invention,"one manner ofputting thesame into practice will be described, reference being made'to theaccompanying diagrammatic drawing illustrating one suitable form of aptus.

Earring more particularly to the drawwhich diagrammatically represents a.verticalsectional view of suitable apparatus,

coal, oil or other suitable material, by pass? yielding hy rogen, carbonand residual gases" and air.

the chamber and produce a hot zone at the through a pipe 16 controlledby a valve 17.

The air for the burning of the deposited carbon enters through a pipe 18having a valve 19, and th'e.,products of the combustion of the carbonleaves through the pipe 20 in which is a valve 21. The air is'suppliedby a blower 18.

Carbon having been deposited on the refractories in the centre zone ofthe checkerwork 13, thehot and cold gas valves 15 and '17 are closed andthe air valve 19 and the stack valve 21 are opened. The passage of thehot .gas on the previous cycle having heated the checkerwork atthe--lower end 22, the incoming air is heated and at the same time thisend of the checkerwork is cooled.

The heated air burns the deposited .carbon causing a high temperature.in the centre 7 zone... This heat is absorbed by the checkerwork andpart of it is carriedout ofthe centre zone by the productsof thecombustion which have also risen to a high temperature from thecombustion. The upper end 23 of the 'checkerworkis cool as the result ofthe. incoming cold gas sweeping over'it in the preceding cycle. The hotproducts of the combustion leaving the centre zone give up most of theirheat to this cooled buckin opposite directions. Under these condigasvalves 15 and 17 are opened. The incomcold gas is heated gradually bythe heat 7 e in the upper zone 23 of thecheckerwork: by the onoingflproducts of the combustion. When this eat temperature so high'that all of the-h drocar bon compounds, such as methane an ethane, aredecomposed. This decomposition is sub- 9 gas reaches the centrezone ofthe checkerwork 13, the gas is carried toa' 90 e air and stack pipes areclosed and the stantially complete at 1500 F., but inpractice thecheckerwork in the centre zone is heated to 1800 F. to shorten the timeof the decomposition. As the cracking is largely brought about by thecontact of the gas with the hot checkerwork, the carbon freed as theresult ofthe cracking isin contact with the checkerwork and adheres toit as a solid deposit. This adherence is facilitated by the fact thatthe carbon, if the temperature is not too high, contains some hydrogen,so that the deposit is in the form of a sticky but hard tar. The gasleaves the centre cracking zone ata high temperature, which is loweredby the absorption of some of itsheat by the brickwork in the lower part22 of the checkerwork, which had been cooled by the incoming cold air inthe-previous combustion 0 dc. The partially cooled gas leaves the ceckerwork through the pipe 16.

These cycles are then alternately repeated. To secure a continuoussupply of hot cracked gas, two checkerworks can be used, each deliveringcracked gas while the carbon is being burned out of the other one, orthe cracked gas can be stored in a gase holder from which gas can besupplied through a pipe 26 during the interval when the carbon is beingburned out of the checkerwork. The gas holder may be of any suitableform such as the inverted bell 24 water sealed in a tank 25.

' With some natural gases, the amount of carbon deposited is so largethat, more .heat would be developed than can be absorbed if all thiscarbon were burned to carbon-dioxide. Under these conditions, the supplyof air can be limited and part of the carbon burned to carbon monoxidewith the production of less heat, yet with the complete removal of thecarbon, due to the high temperature of the combustion and the consequentdisplacement of the condition of chemical equilibrium toward theproduction of carbon monoxide.

Gas or vapors produced from coal, oil or other materials may be crackedin the same way. I

This invention can also be used for cracking the vapors or heavy oilsinto the vapors of hghter oils. All such cracking means the reduction ofthe percentage of carbon inthe vapor, and in this invention thisrejected carbon is deposited on the hot checkerwork and by itscombustion furnishes the required heat for the operation. Where suchheavy oils. have a temperature of vaporization at normal pressure thatis above their decomposition temperature, they may be evaporated atlower pressures into a large volume of gas high in' ydrogenand suchsuspendedvapor may be cracked irt-aceordance with this invention. 'In.such caset tio of carbon tohydrogen will not'only be" ed thedecomposition of a some of the aceo inp "'j'fying carbon but, under th'eunstable condition iii-the oil molecule produced by the hi htemperature, some of the surrounding hy rogen will also be absorbed,further lowering the ratio of carbon to hydrogen in the molecule andcorrespondingly low I ering the boiling temperature of the original oilvapor. p a

Having thus described my invention, what I claim is 1. A processofmaking hydrogen by decomposing hydrocarbon gas, which comprisespassing t e gas in} contact with refractory material of increasingtemperature with exclusion of air, the maximum temperature of saidmaterial being above the decomposing temperature of said gas, and thenof decreasing temperature, the decomposition being accompanied bydeposition of carbon near the material of maximum temperature,subsequently burning said deposited carbon with heated air to re-heatsaid material, and absorbing art of the heat of the products of said comustion in the part of said material with which said gas initially camein contact.

2. A process of making hydrogen by decomposing hydrocarbon vapors whichcom prises passing the vapors in contact with refractory material ofgradually increasing temperature until the temperature of said materialis above the decomposition temperature of said vapor with exclusion ofair a with deposition'upon said material of maximum temperature of thecarbon resulting from the decomposition of said vapor, and then bringingthe gaseous products of said decomposition in contactwith said materialof gradually decreasing temperature subsequently re-heating saidmaterial'at the point of maximum temperature by burning said depositedcarbon with a current of air, passing through saidmaterial-ina-direction contrary to the direction of passage of said vapor.

3. A process of making products of high hydrogen percentage content fromhydrocarbon gas or vapour having hydrogen percentage content lower thanthat of the desired products, which comprises passing the same through arefractory c eckerwork highly heated in its intermediate port'on and'cooler toward-the ends with heating of the gas in the first ortion ofthe chec erwork encountered by t e gas or vapour, cracking of the gas orvapour in said intermediate hot "portion of the checkerwork and depositof carbon therein, and heating of the last portion of the checkerworkencountered by the hot cracked gas, and when the temperature of theintermediate portion of the checkerwork drops below an efiicient gas orvapour cracking temperatureistoppin the gas flow and passing air throughthe c eckerwork in the opposite direction to the gas or vapour withheating of the air in the first part of the checkerwork encountered bythe air, combustion of the deposited carbon in the interof products ofcombustion in the ortion of the checkerwork first encountered y the gasor vapour, cracking the gas or'v'apour in an intermediate portion of thecheckerwork by heat remaining in said portion from burning carbondeposited by a previous cracking operation, heating the portion of thecheckerwork last encountered by the cracked gas with heat carried by thegas out of the cracking zone,

heating air with the heat left in the checkerwork first encountered bythe air from emerging cracked gas, burning carbon deposited in anintermediate portion of thecheckerwork by the previous cracking operi ithe maximum temperature of the refractory hand.

ation with said heated air thereby reheating the checkerwork to crackingtemperature, and reheating the portion of checkerwork first encounteredby the gas or vapour with the heat of the products of carbon combustion.

5. A process of making hydrogen by decomposing hydrocarbon gas, whichcomprises progressively heating the gas to a temperature above itsdecomposition temperature and then progressively cooling the gas, theheating and cooling being effected by passing-the gas in contact with amass of refractory ma-. terial heated to temperatures progressivelyhigher and then progressively lower along the path of the gas.

6. A process according to claim 5, in which the maximum temperature ofthe gas is approximately 1500 F.

7. A process according to claim 5, in which material is approximately 1800 F.

In witness whereof, I have hereunto set my FREDERICK T. SNYDER.

